All manner and variety of devices or appliances configured for the absorption of such body fluids as menses are of course well known. As a class, these articles ought to possess certain necessary attributes of absorbency, comfort and psychological as well as physiological or physical protection. Desirably, these devices also are characterized as being discreet both during wear and when carried upon the wearer's person in anticipation of use. As will be seen from the ensuing discussion, these objectives are somewhat antagonistic in the sense that attainment of one has heretofore ordinarily necessitated compromising one or more other desirable feature.
The art has offered two basic types of feminine protection device with those objectives borne in mind; sanitary napkins or pads have been developed for external wear about the vulvar region of a user while tampons have been developed for residence within the vaginal cavity and interruption of menstrual flow therefrom. Each offers distinct advantages and, as one would expect, distinct or peculiar disadvantages, which range from psychological impediments and/or concerns to physical discomforture. Hybrid devices, attempting to merge the structural features of both within a single type of device, have also been proposed but have not seen a meaningful measure of acceptance insofar as the effort to appropriate advantages has been overshadowed by the more demonstrable perpetuation of structural and anatomically functional disadvantages. Inasmuch as the present invention relates to a labial pad, the foregoing types of feminine protection products are discussed below with that particular thought foremost.
Sanitary napkins, including contoured sanitary napkins such as those described in U.S. Pat. Nos. 4,397,644 and 4,079,739, are well known. Conceptualizing, sanitary napkins of this sort are of multilayered construction including a fluid absorbent core interposed within a backing of a fluid impermeable shield or baffle and a fluid permeable cover, the latter transmitting menstrual fluid or the like across its boundary to the absorbent core. As those skilled in the art will readily appreciate, the interrelationship of components is substantially more intricate; however, for purposes of basic understanding, the foregoing suffices. Within those very general parameters, one may also profitably compare the contoured sanitary napkin disclosed in U.S. Pat. No. 4,184,498. Given that conceptual background, there are several important requirements of such an article. Apart from the self-evident necessity that the core or absorbent member of a sanitary napkin must be constructed to retain menstrual fluid without leakage, there are two other features of conventional designs which warrant further attention in relationship to the present invention. These characteristics regard the cover member of the sanitary napkin and the manner in which the device is secured to or about the body of the wearer.
Dealing with the former first, the conventional wisdom respecting cover members for sanitary napkins dictates a composition or construction which yields a relatively dry and nonsmearing surface. There are both physical reasons and perceptual reasons to strive for those types of features. On the one hand, maximizing so-called "Z directional" flow, through the cover and into the absorbent or fluid retentive core, provides a means for accommodating volumetrically greater discharges of menses during heavy flow conditions. On the other hand, this attribute minimizes the smearing effect and resultant discomfort experienced by the wearer. Psychologically, rapid Z directional flow with relatively dry cover conditions relates to the perception of safety which correlates with the potential for embarrassment upon failure of the napkin. Thus, for example, a major impetus for the improved comfort feature evidenced by, e.g., the invention disclosed and claimed in the aforementioned '644 patent is that type of dry cover with rapid transfer of menstrual fluid thereacross to the fluid retentive core member to achieve those specific goals.
Further along the general lines set forth above, positioning the sanitary napkin relative to the body of the wearer can be an important consideration. Over the last decade or so, sanitary napkins have now routinely been secured within or to the undergarment of a wearer. A move away from the historical tabbed napkin affixed about the body of a wearer by means of a belt or the like to adhesive attachment to undergarments is now almost universally complete in many significant commercial markets. This offers quite an advantage under most circumstances to a wearer as a matter of convenience. Nonetheless, a drawback persists in the nature of rubbing or chafing. More specifically, movement and particularly vigorous movement such as rapid walking or running yields motion between the body of the wearer (and particularly within the vulvar region) relative to an undergarment. Securing a sanitary napkin to the wearer's undergarment therefore translates under ordinary circumstances into relative motion between the wearer's body and the napkin itself, an experience exacerbated in fact as well as sensory perception should the cover fail to provide the features outlined generally above (e.g., a dry, nonsmearing cover). In turn, this can lead to heightened discomfort due to chafing, rubbing, and perhaps even to more intense irritation about highly sensitive tissues of the wearer. To date, these sources of discomfort have been begrudgingly accepted as a necessary concession where one wishes to utilize a sanitary napkin as opposed to a tampon for feminine protection.
Looking to tampons as such an alternative to sanitary napkins, the same are preferred by a substantial number of women. Offering the ability to intercept menses within the vaginal canal, the disadvantages inhering in sanitary napkins in respect of covers and attachment means are overcome by this approach. That is not to say, however, that tampons afford a superior means of feminine protection for all users. For example, there are many individuals who, for either physical or psychological reasons, are unable to utilize tampons as an effective means of feminine protection. Tampons themselves may be found lacking in terms of construction inasmuch as efficacy relies significantly on the ability of the same to undergo radial expansion upon fluid swelling in order to form a seal or zone of occlusion within the vaginal canal. Failure to do so implies overall failure of the tampon to serve as a reliable protection device.
As indicated briefly above, there have been proposals to merge the attributes of sanitary napkins and tampons into a single type of hybrid device. These hybridized appliances are generally classifiable by means of a prominence or projection designed for disposition within the vestibule of the wearer. In some instances, such as that suggested by the disclosure in U.S. Pat. No. 2,092,346, the pad includes a tampon component thereby physically adapting both approaches. That particular device and others of its ilk are typically found quite unacceptable for, amongst other reasons, the projection of a member through the vaginal orifice. Unlike a tampon which resides wholely within the vaginal canal, this type of device maintains constant interposition within the sphincter-like muscularture of the vaginal orifice which is decidedly disadvantageous from a comfort point of view. That discomfort can be substantially intensified where, in following the approach suggested by, e.g. the '346 patent, the element within the vaginal opening is physically secured to an external member whereby relative movement of the wearer and the underlying pad structure compounds the irritating tendencies of the structure. Conceptually similar is the protective shield disclosed in U.S. Pat. No. 3,905,372. Although perhaps less prone to causing irritation within the sensitive tissues of the wearer, many of the same problems are found relative to the projection of an element through the vaginal orifice.
There have been several other approaches suggested in the art which purport or otherwise attempt to avoid the problems mentioned immediately above as regards the interruption of the vagina. For example, U.S. Pat. No. 3,983,873 suggests quite a wide array of geometries for a feminine hygienic pad configured for residence at least partially within the wearer's vestibule. Th patentee places a premium on the use of relatively angular geometries for the structure, including, for example, a substantially abrupt change in transverse dimensions in order to yield shoulder-like configurations at the juncture between the anterior and posterior regions of the pad. Optionally, but preferably, the pad is formed with wings which are resiliently urged toward each other for bearing against the walls of the labial space in order to increase the retentive forces of the pad therein. Consequently, the design offered in the '873 patent is one which requires the sanitary pad to bear against the inner region of the wearer's vestibule which, in turn, is expected to be irritable and lead to discomfort over prolonged periods of use. Other so-called labial sanitary pads are disclosed in U.S. Pat. No. 2,662,527. The patentee in that case describes a pad composed of two portions. The first is deemed a main portion having a length sufficient to extend from a point between the wearer's frenulum and the rectum to a point opposite the anterior of the vestibule. The second portion is formed of one or more layers folded or rolled to yield an element having a somewhat greater height than width and secured or in some efficient manner disposed intermediate the length of the main portion. The second member, borne upon the face of the main member, is dimensioned to fit between the labia of the wearer, bearing against the vaginal orifice; thus, the second element is entirely in residence within the vestibule of the wearer reaching the floor thereof. Of somewhat related interest is the sanitary napkin disclosed in U.S. Pat. No. 3,406,689, insofar as that structure likewise includes an element or second member supported upon the top surface of a sanitary napkin, configured for overlapping disposition about the entire vulvar region and, from there, extending posteriorly of the vestibule of the wearer.
Labial pads of the foregoing varieties, designed with improved absorptive efficiencies as an apparently singular goal, have not properly accounted for the importance of anatomical cooperation with the wearer. Comfort is a lacking feature in use, in the sense that sensitive tissues are oftentimes distended by obtrusive geometries while structural elements of the pads find their way into rubbing contact with similarly highly sensitive urogenital members such as the wearer's vaginal orifice, urethral orifice and/or clitoris. Even short duration wear under such circumstances customarily results in physical reactions ranging from intense discomfort to mild pain. While the device of the '689 patent is perhaps of a design less irritable than, for example, many of the other contoured or profiled hybrid devices noted above, the extension of the napkin into proximate engagement with the wearer's buttocks contributes substantially to chafing or like abrasion, perhaps even physical movement of the napkin out of position due to rearward movement with the buttocks themselves during walking. Irrespective of such considerations, other vestibule-type sanitary napkins are disclosed in U.S. Pat. Nos. 2,331,355, 3,528,422, and 4,046,147, which are similar to those discussed above respecting anatomical functionality; none of which warrant further extended discussion herein but review of which may profitably be undertaken.
A noteworthy configuration for a sanitary napkin, vis-a-vis the structure of the present invention, is disclosed in U.S. Pat. No. 3,073,309, although the same would not likely be classified as a labial pad per se by the skilled artisan. Related closely to that configuration are the generally similar constructions found in U.S. Pat. Nos. 3,117,577, 3,092,109, and 3,121,427. As common factors, these patents disclose a sanitary napkin having means for attaching the same about the body of a wearer and further including a raised element at the distal end of the pad, tapering in both forward and side directions. In the '309 patent this projection is denoted as an "indicating device," included in order to give the wearer assurance that the napkin is properly placed. To achieve that indicating function, the projection is said to be formed in such a way that it seats itself between the wearer's frenulum and rectum projecting upwardly into that region (i.e., the perineum) from the pad. Although expressly distinguished from a labial pad (normally thought to extend into the vestibule) and also a conventional tampon, the patentee there observes that this projection into the perineum will provide an effecting damming action deterring rearward seepage of menses when the wearer is in a lying or supine position. An interesting point is articulated by the patentee in this connection; conventional devices which extend into the vestibule area between the labia contribute to irritation not encountered when the sanitary napkin of that (i.e., '309) reference is utilized, while the "damming" action is nonetheless allegedly attained by virtue of the design of the subject patent.
Devices heretofore proposed for partial or complete interposition within the vestibule of a wearer have uniformly failed to achieve any real measure of success for several reasons. For example, many have been designed simply with ancillary projections or the like for disposition within the vestibule but without overall regard for anatomical vagaries among wearers. In turn, placing a prominence or other projection entirely within the vestibule promotes the kind of irritation noted by the patentee in the '309 reference cited above. Furthermore, certain of the aforementioned designs have been made with an eye toward forcing the vestibule as a conformable tissue to mold about the generally more rigid projection or prominence, not unlike the interrelationship between vestibule and pad required in the '873 patent where the article includes shoulder-like configurations and wing elements as important structural features to ensure anatomical cooperation. Irritation or tendencies toward that effect is most often a consequence where no accommodation is made for the fact that the body of the wearer can have substantial relative movement respecting the pad depending upon the manner in which the latter is associated with the former. As noted above, firmly securing a pad to the undergarment of a wearer with a portion of the pad located within the vestibule will under most circumstances be found to create a rubbing or chafing effect within that very sensitive environment. The attempts summarized above have also failed to take into account the specific nature of that sensitive environment, one which is typically a moist, highly sensitive tissue (said to approach a mucous membrane) in contradistinction to "external" skin. Consequently, adaptation which simply converts a normal sanitary napkin having a cover which is designed, perhaps specifically, to exhibit an advantage of being dry and disposing that within the more moist or hydrous environment of the vestibule can lead to substantial discomfort.
Accordingly, those skilled in the art will readily appreciate that there has yet to be devised a labial pad which achieves the goals set forth throughout the prior art discussed above relative to contoured sanitary napkins but which will overcome the serious disadvantages heretofore proving to be serious impediments to their acceptance, whether viewed technically or commercially. The present invention fulfills that long felt need.